A case of multidrug resistance in the central nervous system.

HIV-1 infection may persist in the central nervous system (CNS) despite antiretroviral therapy. We present a case of severe cognitive decline in a man with HIV-1 infection on a fully active regimen for five years. All infective causes were excluded. Despite fully suppressed virus in the blood, HIV RNA in the cerebrospinal fluid measured 3.52 log(10) RNA copies/mL and genotyping of this sample showed an extensive pattern of resistance. This suggested that either the antiretroviral agents were not adequately penetrating the CNS or the CNS had resistant virus as a result of adherence problems. This case highlights the possibility that drug-resistant mutations may develop in the CNS compartment while plasma virus remains suppressed.